There are No Free MBR Slots on the Disk in Windows 10 - Fixed

There are no free MBR slots on the disk error

Some users of Partition Wizard report that they received the “No free MBR slot” or
“There are no free MBR slots on the disk” when they try to create a partition with
unallocated space of selected disk in Windows 10. The error occurs on MBR disk
usually and also happens when splitting or extending the specified partition. What’s
wrong?

According to the FAQ of Partition Wizard, there are two scenarios may cause such
error. Firstly, there are already four primary partitions on the disk. Secondly,
there are three primary partitions and one or more logical partitions on the disk.
Therein, the unallocated space that used to create a partition does not adjacent to
the logical drive. That is to say, it cannot be created as a Logical drive. However,
based on the primary partition limit of MBR, it cannot be created as Primary
partition as well. Thus, error emerges.

The solution provided by Partition Wizard for both situations is to change primary
partition to logical with the feature of “Set partition as logical”. However, except
for that solution, you can try other attempts.

Fix No free MBR slots in two effectively ways

When fails to create partition with Partition Wizard, it is not a bad choice to
choose other workarounds to achieve the goal. Two simple methods to solve no free
MBR slot error will be introduced in following parts. Take the one that is suitable
for you.

Assign a drive in Windows Disk Management

2. In Disk Management, right click the unallocated space and select New
Simple Volume.

3. Follow the wizard to complete the creating.

It is simple and fast. However, you may get this prompting message “You cannot create
a new volume in this unallocated space because the disk already contains the maximum
number of partitions” if there are already four primary partitions on the disk. As a
result, you need to turn to another way to settle no empty slot in MBR table
issue.

Fix “there are no MBR slots” by converting GPT without data loss

Many users want to keep all partition on the selected disk as primary partitions due
to various reasons. Under such circumstances, it is a wise move to convert disk to
GPT to break the limitation of MBR. AOMEI
Partition Assistant Professional allows you to convert MBR to GPT disk
without formatting, whether you want to convert the system disk or the data disk.
Please make sure your computer support UEFI boot if you’d like to convert system
disk. Then, let’s see how to solve “there are no free MBR slots on the disk” in
Windows 10 in simple three steps.

Conclusion

You can fix “There are no free MBR slots on the disk” error with three ways in total,
convert primary to logical, assign drive in Disk Management and convert GPT to break
the limit. As a matter of fact, AOMEI Partition Assistant is able to create
partition, extend partition, shrink partition and split partition for you. More
advanced operations like make bootable media, SSD secure erase, migrate Windows 10 to
SSD, etc. is supported by the software.